Transcript
GROUND STRAP TESTERS
Series 250
Features Precision ground strap resistance measurement Automatic upper / lower resistance tests Fail safe design with automatic self check PASS / FAIL indicators with audible alarm
Complies with ESD Association & NAVSEA Standards Portable, bench or wall mount Battery and AC powered models Resistance to ground testers
Applications The potential for damage caused by a static charge build-up on personnel involved in the handling of sensitive semiconductor devices or flammable material has been clearly established. Grounding wrist straps, heel straps and footwear are the most commonly used protective devices which prevent the build-up of electrostatic charge on personnel. The random failure of a ground strap or ground connection compromises the protection it provides and can also create a potentially lethal shock hazard. The ETS Series 250 Ground Strap Testers are precision instruments that check the specified resistance limits of all types of wrist straps and other similar personnel grounding devices plus instruments to measure resistance to ground of the groundable point. The Model 250 is a battery powered, lightweight, low cost instrument that can be placed on the workbench or carried by supervisory personnel to quickly and efficiently check the strap and wearer and the wrist strap alone. The Model 252C is a wall mounted version of the Model 250 that is AC powered and also checks heel grounders and footwear. The Model 253A is a militarized version that tests both ESD and Ordnance type ground straps. The Model 255 measures resistance to ground.
Series 250
Measures the electrical integrity of personnel grounding systems.
Description Ground Strap Testers - The Series 250 Ground Strap Testers automatically measure the resistance of ground straps and clearly indicate whether or not their resistance is within precise lower and upper limits. For ESD applications where the required strap resistance is 1 Megohm, a lower limit of 750 kOhms is utilized and upper limits of either 1.25 Megohms or 10 Megohms are used for the STRAP ONLY and the STRAP and WEARER test modes respectively. For Ordnance applications where the nominal strap resistance is 50 kOhms, the lower measurement limit is 45 kOhms and the upper limits are 55 kOhms and 1 Megohm for each test mode. A 2-position switch on the Model 250 enables the user to select either the STRAP ONLY mode or the STRAP and WEARER mode. A 3-position switch on the Model 252C tests wrist straps, as with the Model 250, and heel grounder and ESD footwear resistance up to 100 Megohms. The Model 253A accommodates both Ordnance and ESD ground straps and uses a 4-position selector switch to set the resistance test limits for each ground strap type. The Ground Strap Testers incorporate both visual and audible indicators and a unique fail-safe design with automatic self-check. Each time the tester is operated, the FAIL audio / visual indicators are momentarily activated prior to the actual test ensuring that both the FAIL and PASS modes are working. When a defective strap is tested, the FAIL Red LED indicator will flash continuously and the audible alarm will continue to sound. When a good strap is tested, the FAIL Red LED will flash and the audible alarm will sound for approximately one half second; the PASS Green LED indicator will then light and remain lit for as long as the TEST button is depressed.
The 252C and 253A are AC powered and utilize transformer coupling to achieve AC isolation. The grounded AC power supply enables heel grounders and footwear attached to personnel to be tested without any additional connections when used in conjunction with grounded floor systems. A 12” x 12” stainless steel footplate is available with the Model 252C for direct heel grounder and footwear testing. The Model 250 incorporates a single banana jack input connector to acommodate industry standard wrist straps. Optional input connectors are available to also accommodate both .25” and .375” snaps. Alligator clips can easily be attached to either the snap or to a banana plug adaptor. The Models 252C and 253A incorporate all three types of connectors as standard so that virtually all types of ground straps can be tested. Resistance To Ground Testers - The Model 255 Resistance To Ground Tester verifies the bonding resistance to ground is <1 or <2 ohms as selected by the user. This hand held, battery-powered instrument enables the user to make fast, accurate checks of AC outlet ground and point-to-ground connections. Five foot cables with standard banana jacks and removable alligator clips are included. The Model 256 Utility Wiring Verifer provides both a quick, accurate check of AC outlet (US Std.) wiring and a standard banana jack to access electrical ground.
Options Customized resistance limits can be provided to meet special user requirements.
Specifications Resistance Threshold Limits: ESD (1 Megohm nominal resistance) Lower Limit: 750 kOhms ±2% Upper Limit: STRAP ONLY - 1.25 Megohms ±2% STRAP & WEARER - 10 Megohms ±10% FOOTWEAR - 100 Megohms ±10% ORDNANCE (50 kOhms nominal resistance) Lower Limit: 45 kOhms ±2% Upper Limit: STRAP ONLY - 55 kOhms ±2% STRAP & WEARER - 1 Megohm ±2% RESISTANCE TO GROUND: <1 or <2 Ohms Indicators: FAIL: Flashing Red LED / pulsating audible alarm Continuous Red LED (Model 255) PASS: Continuous Green LED Input Connectors: Models 250 & 255: Standard Banana Jack Models 252C & 253A: Standard Banana Jack .25” Snap .375” Snap Test Voltage (Models 250, 252C & 253A): 5 Volts
Applicable Specifications: ESD S1.0-95 NAVSEA OP5, 4th Rev. Power:
Models 250 & 255: single 9 Volt alkaline battery Life: 1 year min. under normal use (300 tests / day) Models 252C and 253A: 110 / 220 VAC, 50 / 60 Hz Fuse: 3AG 1/ 4 Amp Line Cord: 3 cond., 8 ft. Dimensions: Models 250 & 255: Case: ABS Plastic Size: 3.75”L x 2.25”W x 1”H Weight: 5 oz. Models 252C & 253A:
Case: ABS Plastic Size: 4”L x 4”W x 2”D Weight: 1.25 lbs.
Options: Custom upper / lower threshold limits Special input connectors 12” x 12” stainless steel plate Warranty: Models 250 & 255: Ninety (90) days Models 252C and 253A: One (1) year
In accordance with ETS policy to improve our product line, the specifications cited above are subject to change without notice.
electro-tech systems, inc. 3101 Mt. Carmel Avenue, Glenside, PA 19038 • Tel: (215) 887-2196 • Fax: (215) 887-0131 9/97
